1. Field of the Invention
The present invention relates to an air separation apparatus having an air vent assembly, which is capable of separating gas from circulating cooling and/or heating water in cooling and/or heating systems and expelling the separated gas into the atmosphere.
2. Description of the Conventional Art
In general, residential buildings, factories and large-sized buildings adopt a cooling or heating system for control the indoor temperature, in such a manner that liquid such as water flowing in the pipes is cooled or heated, and forcedly circulates through the pipes by means of circulating pumps so as to exchange its chill or heat with the pipes. In the cooling and/or heating system, continuous and smooth circulation of the liquid is decisive of the efficiency of the cooling and/or heating system.
However, gas is dissolved or entrained in the liquid and/or present in the liquid in the form of gas bubbles. The gas tends to separate from the water in response to changes of external temperature or pressure.
When the gas separates from the liquid, the gas, which circulates with the liquid through the pipes in the form of gas bubble like a small drop, becomes an obstacle to the smooth circulation of the water. Further, oxygen dissolved in the liquid corrodes inner walls of the pipes and contaminates the water.
Therefore, it has become a serious problem to thoroughly expel the gas separated from the water into the atmosphere, without any residual gas.
In order to resolve the disadvantages, in view of that the oxygen and air separated from the water have small gravity and the air goes upwards, an additional air separation apparatus having an air-vent has been suggested to be installed in the middle of the pipes for separating oxygen and air dissolved in the water to expel the separated air to the atmosphere.
Referring to FIG. 1, as an example, in a conventional air separation apparatus, an inlet pipe 110 and an outlet pipe 120 are respectively connected with pipes H, H'. The inlet 110 is extended inward to a pressure pipe 130, which have a plurality of holes 140 to circulates water into the air separation apparatus 100. The air separation apparatus 100 is provided with an air vent 200 to collect air which is separated by the pressure pipe 130.
As shown in FIG. 2, in the air vent 200, an opening lid 210 includes an air outlet 220 and is provided with a link 230. The link 230 is mounted in a main body 240 and includes an end part, which is fixed at a lower part of the outlet 210, and the other end part, which moves up and down in response to up/down movement of a float according to change of water level, thereby opening/closing the air outlet 220.
According to the conventional air separation apparatus as described above, water is introduced through the inlet 110 and passes through the holes 140 of the pressure pipe 130 and guided inside the air separation apparatus 100. At this time, pressure change of the water passing through the holes 140 of the pressure pipe 130, that is, the pressure difference of the water between before and after passing through the pressure pipe 130, makes it possible to separate air from the passing water. The separated air combines together to make a bubble 9 (airdrop) and rises upward in the air separation apparatus 100, thereby entering into the air vent 200.
If the pressure difference in the air vent 200, that is, if the pressure of the water is lower than that of the air, level of the water becomes higher and raises the float 250 up so that the float 250 lifts the link 230 upward, thereby closing the air outlet 220. Conclusionally, the air, which is separated from the water by the air separation apparatus 100 and enters into the air vent 200, can not be discharged into the atmosphere.
If the air escapes into the atmosphere, lowering the air pressure in the air vent 200, water is introduced inside the air vent 200 again. Then, in response to the increase of the water level, the float 250 is lifted upward again so that the air outlet 220 is closed. The above-described operation is repetitively performed and the air separated from the water may escape the air vent 200 into the atmosphere.
However, the conventional apparatus has disadvantages that it is impossible to completely separate the air from the water by the pressure difference of the water which passes through the holes of the pressure pipe and the flow of the water becomes slow suddenly since size of the holes of the pressure pipe is small.
The conventional apparatus has further disadvantages that the opening/closing structure of the air outlet is complicated since the air outlet is opened/closed in response to the up/down movement of the link by means of the float which moves up and down in inverse proportion to amount of air, that is, pressure of the air which is introduced into the air vent.
Further, the link comes into contact with the float at one point, so that the lifetime of both link and the float becomes decreased. Furthermore, since the main body and the opening lid are made by metal casting, the manufacturing cost thereof may be increased.